Dustin Johnson's previously commanding position at the top of the Masters leaderboard was left looking a little less dominant after his lead was cut to two at the halfway point of the final round on Sunday.

The world number one enjoyed a near flawless outing a day earlier, his seven-under-par 65 helping him to equal the 54-hole record set by Jordan Spieth in 2015 and open up a four-shot lead over Cameron Smith and Sungjae Im.

But an early wobble offered encouragement to the chasers, particularly the impressive Smith, who found himself as Johnson's closest competitor at the turn.

Having parred the first, Johnson then showed signs of unease as he scrambled to avoid dropping a shot on the par-five second.

A birdie at the third proved a false dawn of sorts as back-to-back bogeys followed.

At the same point, Im was two under for the day and seemingly closing on Johnson, only for the South Korean's bogey at the sixth to set him back.

However, at the halfway point it was Smith – a Masters debutant, like Im – who appeared the most likely to knock Johnson off the summit, the Australian just two adrift having been four off the pace at the start of the day.

Smith made it to the turn in 33, his remarkable approach shot from a bed of pine needles setting up his fourth birdie of the day on the ninth.

Elsewhere on the course, five-time Masters champion Tiger Woods endured a torrid time on the par-three 10th, incredibly carding a 10 after three visits to Rae's Creek